138235218 has 16 divisors (see below), whose sum is σ = 301604256. Its totient is φ = 41889440.

The previous prime is 138235213. The next prime is 138235249. The reversal of 138235218 is 812532831.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is not an unprimeable number, because it can be changed into a prime (138235213) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1047171 + ... + 1047302.

It is an arithmetic number, because the mean of its divisors is an integer number (18850266).

Almost surely, 2^138235218 is an apocalyptic number.

138235218 is an abundant number, since it is smaller than the sum of its proper divisors (163369038).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

138235218 is a wasteful number, since it uses less digits than its factorization.

138235218 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2094489.

The product of its digits is 11520, while the sum is 33.

The square root of 138235218 is about 11757.3474049209. The cubic root of 138235218 is about 517.0583634401.

The spelling of 138235218 in words is "one hundred thirty-eight million, two hundred thirty-five thousand, two hundred eighteen".